Cipher

About: Cipher is a(n) research topic. Over the lifetime, 9409 publication(s) have been published within this topic receiving 110309 citation(s). The topic is also known as: cypher & cryptographic algorithm.

PRESENT: An Ultra-Lightweight Block Cipher

Abstract: With the establishment of the AES the need for new block ciphers has been greatly diminished; for almost all block cipher applications the AES is an excellent and preferred choice. However, despite recent implementation advances, the AES is not suitable for extremely constrained environments such as RFID tags and sensor networks. In this paper we describe an ultra-lightweight block cipher, present . Both security and hardware efficiency have been equally important during the design of the cipher and at 1570 GE, the hardware requirements for present are competitive with today's leading compact stream ciphers.

PRESENT: An Ultra-Lightweight Block Cipher

Abstract: With the establishment of the AES the need for new block ciphers has been greatly diminished; for almost all block cipher applications the AES is an excellent and preferred choice. However, despite recent implementation advances, the AES is not suitable for extremely constrained environments such as RFID tags and sensor networks. In this paper we describe an ultra-lightweight block cipher, present . Both security and hardware efficiency have been equally important during the design of the cipher and at 1570 GE, the hardware requirements for present are competitive with today's leading compact stream ciphers.

Efficient Fully Homomorphic Encryption from (Standard) LWE

Abstract: We present a fully homomorphic encryption scheme that is based solely on the(standard) learning with errors (LWE) assumption. Applying known results on LWE, the security of our scheme is based on the worst-case hardness of ``short vector problems'' on arbitrary lattices. Our construction improves on previous works in two aspects:\begin{enumerate}\item We show that ``somewhat homomorphic'' encryption can be based on LWE, using a new {\em re-linearization} technique. In contrast, all previous schemes relied on complexity assumptions related to ideals in various rings. \item We deviate from the "squashing paradigm'' used in all previous works. We introduce a new {\em dimension-modulus reduction} technique, which shortens the cipher texts and reduces the decryption complexity of our scheme, {\em without introducing additional assumptions}. \end{enumerate}Our scheme has very short cipher texts and we therefore use it to construct an asymptotically efficient LWE-based single-server private information retrieval (PIR) protocol. The communication complexity of our protocol (in the public-key model) is $k \cdot \polylog(k)+\log \dbs$ bits per single-bit query (here, $k$ is a security parameter).

Symmetric Ciphers Based on Two-Dimensional Chaotic Maps

Abstract: In this paper, methods are shown how to adapt invertible two-dimensional chaotic maps on a torus or on a square to create new symmetric block encryption schemes. A chaotic map is first generalized by introducing parameters and then discretized to a finite square lattice of points which represent pixels or some other data items. Although the discretized map is a permutation and thus cannot be chaotic, it shares certain properties with its continuous counterpart as long as the number of iterations remains small. The discretized map is further extended to three dimensions and composed with a simple diffusion mechanism. As a result, a symmetric block product encryption scheme is obtained. To encrypt an N×N image, the ciphering map is iteratively applied to the image. The construction of the cipher and its security is explained with the two-dimensional Baker map. It is shown that the permutations induced by the Baker map behave as typical random permutations. Computer simulations indicate that the cipher has g...

An optimal class of symmetric key generation systems

Abstract: It is sometimes required that user pairs in a network share secret information to be used for mutual identification or as a key in a cipher system. If the network is large it becomes impractical or even impossible to store all keys securely at the users. A natural solution then is to supply each user with a relatively small amount of secret data from which he can derive all his keys. A scheme for this purpose will be presented and we call such a scheme a symmetric key generation system (SKGS). However, as all keys will be generated from a small amount of data, dependencies between keys will exist. Therefore by cooperation, users in the system might be able to decrease their uncertainty about keys they should not have access to.The objective of this paper is to present a class of SKGS for which the amount of secret information needed by each user to generate his keys is the least possible while at the same time a certain minimum number of users have to cooperate to resolve the uncertainty of unknown keys.